It seems like I need to turn the right-hand side into an addition expression. I can convert it to a product by expressing as , but I don't know what to do next to get it to an addition expression. Perhaps that's not the right strategy?

When in doubt, do what you can with what you have, and see where that leads. With luck, you'll start seeing something helpful.

I find this to be one of the most frustrating things about math. It seems like so much of it is rooting around aimlessly in the hope of stumbling upon something. It seems like, for being an "exact" science, it should be more exact.